Question Turning on both AC kills generator. Runs fine when plugged in.

[KellieB]

ACs run fine individually, but when you turn both on it kills the generator. It sparks behind the fuses, where the ACO solonoid is located. Any ideas? Already changed the solonoid out, and it still sparks and buzzes.

 

[Dona40]

What size is the Generator?

 

[KellieB]

5500 onan it has always run them before. Can run one or the other, but as soon as you turn on both the generator shuts off.

 

[Joe Dutchstar]

The spec sheet claims this generator can run two 15000 btu air conditioners.

However Sparks are never a good thing. I'd check all the wiring connections and circuits prior to attempting to use the generator again.

https://powersuite.cummins.com/PS5/PS5Content/SiteContent/en/Binary_Asset/pdf/Consumer/specsheets/a-1425.pdf

 

[Papakirk]

ACs run fine individually, but when you turn both on it kills the generator. It sparks behind the fuses, where the ACO solonoid is located. Any ideas? Already changed the solonoid out, and it still sparks and buzzes.

I personally would start with sparks behind the fuse block make secure connection then maybe replace start Is capacitor on the air conditioners. But maybe have somebody checked them 1st

 

[Joe Dutchstar]

Here is a primer on solenoids

 

[Joe Dutchstar]

Depending on the year and model of Onan Generator there can be some differences in solenoid type

 

[KellieB]

Oh, didn’t know about these. I replaced the solenoid inside the coach, behind these plug in fuses. That is where it makes the buzzing noise and sparks. It still does it even when replaced. Generator runs fine and air runs fine individually. Just when you turn on both, it cuts off. You would think it would trip the fuse on the generator , but it doesn’t. It always ran both before. Each air is approximately 10-11 amps.

 

[KellieB]

Oh, didn’t know about these. I replaced the solenoid inside the coach, behind these plug in fuses. That is where it makes the buzzing noise and sparks. It still does it even when replaced. Generator runs fine and air runs fine individually. Just when you turn on both, it cuts off. You would think it would trip the fuse on the generator , but it doesn’t. It always ran both before. Each air is approximately 10-11 amps.

Don’t know where that dog pic came from!

 

[Joe Dutchstar]

Check the wiring of the solenoid and verify the solenoid not shorted.

 

[Joe Dutchstar]

This might help

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www.myelectricworks.com

 

[KellieB]

Thanks. Maybe the person that put the new solenoid in doesn’t have it hooked up correctly. It is in a very difficult location and quite a few wires. Need to find a diagram of how it is supposed to be.

 

[Dona40]

One thought. Have you verified that the Generator will continue to run on a heavy load separate from the RV? If you have a fuel system/ignition problem that bogs the engine down under a heavy load, it could possibly make that switch over relay go a little nuts. Not being there makes it harder to diagnosis of course.

 

[KellieB]

One thought. Have you verified that the Generator will continue to run on a heavy load separate from the RV? If you have a fuel system/ignition problem that bogs the engine down under a heavy load, it could possibly make that switch over relay go a little nuts. Not being there makes it harder to diagnosis of course.

I just changed the fuel pump and filter, but no difference. I am going to try putting a larger load on it without the back air and see what happens.

 

[KellieB]

I just changed the fuel pump and filter, but no difference. I am going to try putting a larger load on it without the back air and see what happens.

I checked the acs each running with the microwave and it didn’t die. Is the back air only supposed to turn go through the 20 amp breaker ? I shut off the 30 amp breaker and only the front air would come on. Nothing else. I shut that off and turned on the 30 amp breaker. The front and back air would each work individually, all outlets and microwave. Maybe both airs are going through the 30 amp instead on one on each breaker?